FIG. 4(a) and FIG. 4(b) are a cross section diagram and a plan diagram of a conductor crimping portion 112 of a common crimping terminal, and FIG. 5 shows a cross section of the conductor crimping portion 112 swaged around a conductor W of an electric wire (see; for instance, Patent Document 1).
The conductor crimping portion 112 of the crimping terminal is usually formed from a bottom plate 121 and a pair of conductor swaging pieces 122, 122 so as to assume a substantially U-shaped cross section such that the bottom plate 121 becomes slightly curved. The pair of conductor swaging pieces 122, 122 extend upward from both side edges of the bottom plate 121 and are inwardly rolled so as to wrap the conductor W of an electric wire laid on an interior surface of the bottom plate 121 and swaged in such a way that tip ends of the respective conductor swaging pieces are engaged in the conductor W.
In many cases, contrivance is made to the crimping terminal of this type to enhance connectivity between a conductor and a terminal achieved when the crimping terminal is swaged to the conductor by forming indentations, or also called serrations 123 (see FIG. 5), in an interior surface of the conductor crimping portion 112 in the form of a trench or dot pattern (see; for instance, Patent Document 2).
Incidentally, it has already been known that, when the conductor crimping portion 112 is swaged to the conductor W of the electric wire, dimensional accuracy (a depth and a width) of the serrations 123 formed in the interior surface of the conductor crimping portion 112 greatly affect subsequent crimping performance. For this reason, under the present circumstances, an appropriate number of products created on a terminal manufacturing line is sampled and subjected to offline inspection by use of a measuring instrument, like a laser displacement meter.